Here’s the long and short of it: “Harry Potter and the Sorcerer’s Stone” is good, but not great.

Director Chris Columbus had the unenviable task of trying to make a blockbuster movie while simultaneously pleasing fans who will be angry if ANYTHING is changed or — heaven forbid — deleted. Many readers were saying, “We want it to be EXACTLY like the book, AND we want it to be a great movie.”

Well, sorry, but that’s impossible. Movies and books are different things. To be successfully adapted, books must be altered, streamlined and sometimes refocused, or else the transfer to the big screen won’t work.

Columbus erred on the wrong side: The film is so meticulously faithful to the book that it almost doesn’t work as a movie. So intent was he on getting all the book’s physical elements in that he neglected the intangibles. Hogwarts is Gothically gorgeous, the characters look the way we always pictured them and Fluffy the three-headed dog is scary. But the major themes of friendship and courage, not to mention the book’s wicked sense of humor, are given only cursory attention. There’s no time to establish nebulous things like “loyalty”; we’ve got to throw together a Quidditch match!

There’s also this problem: The book is mostly exposition. It is a long time before the real story, about the plot to steal the sorcerer’s stone, kicks into high gear. The movie is the same way. In a book, that works fine. In a movie, it’s considered poor pacing. If I hadn’t read (and loved) the book, about an hour into the movie I’d have been saying, “OK, this stuff is neat and everything, but where’s it heading?”

The actors who play Harry, Ron and Hermione — Daniel Radcliffe, Rupert Grint and Emma Watson — are charming kids and reasonably good actors. Very few of the other characters get the screen time they deserve — Snape (Alan Rickman) and Quirrell (Ian Hart) are most badly robbed — but Robbie Coltrane, Richard Harris and Maggie Smith make the most of it as Hagrid, Dumbledore and McGonagall. (And poor Neville Longbottom: We hardly knew ye.)

The Quidditch match is spectacularly exciting, as are all the special effects. The troll, the goblins, the ghosts — they’re here, and they’re fantastic. It’s amazing how things look just the way the readers imagined them; I literally gasped when I saw the Gryffindor common room — a rather ordinary locale — looking exactly the way I’d pictured it in my head.

The movie is essentially a procession of people and things that have previously lived only in our imaginations. The extent to which you are eager to see such a parade, regardless of how detached the floats are from each other, is the extent to which you will enjoy the movie.

What’s missing is the feeling of magic and wonderment the book gave us. It’s like a cloning experiment gone awry. It appears to be an exact duplicate of the book, and in many ways it is. But somehow, it’s just not the same.